Development of a Speed Modulated Accessory Drive System for Transit Buses

The paper describes the design of a new accessory drive system suitable for transit and highway buses. In a transit bus environment, the accessories consume more power than the drive energy up to about 65 Km/h. The new system provides a constant speed drive for the accessories allowing for more efficient operation and downsizing of the components. The use of the system also allows greater layout flexibility of components for the engine compartment designer. The system makes use of a mass produced automotive continuously variable transmission from Van Doorne Transmissions in Holland.

An analysis of the power requirements, description of the installation layout and analysis of the component downsizing potential is presented. Description of the modifications to the basic automotive transmission is also provided.